分會
第六十一分會:能源化學
摘要
生物質(zhì)由于來源廣、微觀形貌豐富、孔隙結(jié)構(gòu)發(fā)達、成本低等優(yōu)點,被廣泛用于多孔碳材料的合成,進而應(yīng)用于超級電容器的研究。 本文以玉米秸稈為前驅(qū)體,采用簡單的炭化法成功地合成了分級多孔碳。然后通過原位還原法將銀納米粒子負載到玉米秸稈基多孔碳(CSPC)表面,制備出CSPC-Ag復(fù)合電極材料(圖1a),并對其電化學性能進行了研究。同時以玉米秸稈為前驅(qū)體,采用一步碳化加水熱法制備了NiCo2O4六方納米板與三維多孔碳復(fù)合材料,可有效提高超級電容器的電化學性能。CSPC-Ag具有發(fā)達的微孔、介孔及大孔分級孔道結(jié)構(gòu),通過優(yōu)化Ag負載量(5 wt%),其比表面積可高達1140.8 m2/g,在0.5 A g-1 電流密度下進行恒電流充放電測試,其比電容達到323 F g-1(純CSPC為185.7 F g-1)(圖1b)。通過穩(wěn)定性的測試,發(fā)現(xiàn)循環(huán)4000次后,比電容仍保持在初始值的93.2%(圖1c),并以此為電極組裝的超級電容器能量密度可達44.97 Wh/kg,性能優(yōu)于商業(yè)報道的碳基超級電容器。與CSPC或單一NiCo2O4納米板相比,制備的復(fù)合材料具有較高的比電容和較長的循環(huán)壽命,這是由于CSPC具有高導(dǎo)電的富含孔隙結(jié)構(gòu),NiCo2O4具有高能量密度、良好的氧化還原性能和較短的離子傳輸通道。在6 M KOH電解液中,當電流密度為0.5 A g-1時,比電容可達959.2 F g?1;在電流密度為20 A g-1時,循環(huán)次數(shù)超過5000次,電容保持率可達93%,表明該復(fù)合材料可作為開發(fā)高性能超級電容器的優(yōu)秀電極材料。本研究的初步結(jié)果也為開發(fā)高性能超級電容器電極材料以及實現(xiàn)農(nóng)業(yè)廢棄玉米秸稈的高附加值轉(zhuǎn)化和利用提供了一個可行的思路。 關(guān)鍵詞:生物質(zhì);多孔碳;銀納米粒子;六邊形NiCo2O4納米片;超級電容器; Fig. 1 (a) XRD patterns of CSPC-1 and CSPC-1-5% Ag; (b) GCD curves of CSPC and CSPC-Ag at a current density of 0.5 A g-1; (c) Cyclic performance of CSPC-1 and CSPC-1-5% Ag. Cornstalk- Based Hierarchical Porous Carbon Materials for High Performance Supercapacitors Rui Wang, Xinyi Li, Jiali Yang, Meiyu Yang, Yang Zhao, Huan Wang* College of Chemistry and Chemical Engineering, Northeast Petroleum University, Daqing 163318, China *Email: huanw@nepu.edu.cn In this work, hierarchical porous carbon was synthesized by simple carbonization methods using cornstalk as a precursor. Then the CSPC-Ag composite electrode material was prepared using a in-situ reduction method by loading Ag nanoparticles onto the surface of corn stover based porous carbon (CSPC), and its electrochemical performance was studied Here, the one-step carbonization process plus hydrothermal method is proposed to prepare the composite of NiCo2O4 hexagonal nanoplates and three-dimensional porous carbon using cornstalk as the precursor, which can effectively enhance the electrochemical properties of supercapacitors. CSPC-Ag has developed microporous, mesoporous and macroporous porous structure. By optimizing Ag load (5 wt%), its specific surface area can reach 1140.8 m2/g. Constant current charge-discharge test is conducted at 0.5 A g-1 current density. Its specific capacitance reaches 323 F g-1 (185.7 F g-1 for pure CSPC). Through the stability test, it is found that the specific capacitance remains at 93.2% of the initial value after 4000 cycles, and the energy density of the supercapacitor assembled with this electrode can reach 44.97Wh /kg, and the performance is better than that of the carbon based supercapacitor reported by commercial reports. Compared with the bare cornstalk-derived porous carbon (CSPC) or single NiCo2O4 nanoplates, the as-prepared composite exhibits high specific capacitance and long cycle life, which can be ascribed to the integration of the merits of CSPC with highly-conductive pore-rich structure and NiCo2O4 with high energy density, good redox property and short ion transport channel. The specific capacitance can reach 959.2 F g?1 in 6 M KOH electrolyte at a current density of 0.5 A?g?1, as well as the capacitance retention of 93% at a current density of 20 A?g?1 over more than 5000 cycles, indicating that this composite can be considered as an outstanding electrode material for the development of high-performance supercapacitors. Keywords: Biomass resource; Porous carbon; Ag NPs, NiCo2O4 hexagonal nanoplates; Supercapacitor;
關(guān)鍵詞
生物質(zhì);多孔碳;銀納米粒子;六邊形NiCo2O4納米片;超級電容器
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